The present invention relates to an improved power tool, and more particularly, an improved mortiser and accessories therefor.
Power tools, such as hollow chisel mortisers, come in various designs and arrangements. Generally, mortisers include a work table mounted on a base, which can be positioned on a stand or table, or on the ground, a support post which extends above the table and on which a motor for carrying a tool, such as a chisel, is mounted for movement of the chisel in a vertical direction towards and away from the working surface of the table. Additionally, a fence disposed perpendicular to the table's surface is mounted on the table for movement along the table, and a material stop or hold down mechanism, generally mounted on or to the rear of the fence, is provided for holding down a workpiece on the table surface and/or against the fence. One problem with such hold-down mechanisms has been slippage while the mortiser is in use. Moreover, the range of vertical movement of the hold-down mechanism, in order to hold down various size workpieces to the table, is generally rather limited, particularly in the downward direction, in view of the interference with the vertical movement of the hold down mechanism caused by the fence. Additionally, the known hold-down mechanisms generally utilize a simple setscrew mechanism to hold a bracket used as a material stop. This leads to such hold-down mechanisms being prone to slippage, not being flexible in order to hold down various odd shaped workpieces, except with great difficulty, and having a mechanism that cannot extend close to the work table surface, and thus positively clamp relatively thin workpieces, except with the use of additional blocks or shims.
A further problem with known mortisers is that the motor utilized to drive the mortising tool (e.g., chisel and auger which may collectively be referred to hereinafter as a chisel), is in general a constant speed motor, and thus is not available for customization of the auger speed to an application. Thus, the use of a fixed speed for the mortising tool often leads to either high-speeds which may cause chisel “burn” or low-speeds which may cause unwanted resistance when using the mortiser. In addition, certain other variables of the use of the mortiser, including various chisel sizes, the hardness of the wood being mortised, the sharpness of the chisels, etc., are affected by the speed. However, current mortising machines do not provide for any mechanism for taking the motor speed into consideration.
In addition to the above, it has become customary in mortisers to provide a caddy for the mortising tools, as well as for other tools necessary for operation of the mortiser, directly on the mortiser in order to provide ease in changing chisels and/or making such tools readily available and accessible. One common problem with mortising tools is that they often need sharpening, which requires special tools. However, none of the mortisers currently available provide any arrangement for easing the steps of sharpening the chisels or provide any consideration for handling this problem.